This is a very nearly chinless lady on Metro, done in PR Velvet Black ink, later messed up at home with gouache. (I may like this kraft-colored watercolor paper better than the kraft paper. Hmmm!)
I am attempting to see how portable gouache is. It has such a tendency to dry out and crack apart, that it may not be very plein-air-ish. Keeping it soft enough to stay put and solid enough to stay put, simultaneously, is tricky.